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  Mission InSight

Philippe Lognonné

Listen to the heartbeat of Mars: France participates in the InSight Mission

IPGP, CNES, University Paris Diderot - Paris Sorbonne Cité and laboratories French and European research provide the seismometer SEIS, the main instrument of the Mars InSight mission selected by NASA under its Discovery program to explore the solar system.

The InSight mission

Artist drawing of the rover for the InSight mission to Mars. (© JPL/NASA)

Proposed by the Jet Propulsion Laboratory of NASA, InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport ) aims to deploy for the first time, a geophysical station on the floor of the red planet to study the structure and composition of the interior of Mars.
The objective is to better understand the formation and evolution of Mars by providing constraints on its internal structure, still poorly understood. Through the use of sophisticated geophysical instruments , InSight will measure seismic activity in Mars, the internal heat flux and the subtle variations of rotation of the planet.
The SEIS ( Seismic Experiment for Interior Structures) instrument listen " heart beat " of the planet , taking precise measurements of earthquakes and other internal activities to better understand the history of Mars and its structure. While the instrument Heat Flow and Physical Properties Package ( HP3 ) provided by the German Space Agency (DLR) , will sink up to 5 m in the Martian subsurface , to measure the heat flux of the planet and to deduce its cooling rate and thus the power dissipated by the planetary drive.


The SEIS instrument: a real technological challenge

(© IPGP/ P.Lognonné)

SEIS seismometer for InSight mission delivered to Toulouse Space Centre.

Monday 20 July, the Institut de Physique du Globe de Paris (IPGP1) and contractor Sodern delivered the SEIS Mars seismometer to CNES. SEIS is a titanium sphere housing three very-broad-band seismic sensors that form the core of the instrument. Once on the surface of Mars, these miniaturized sensors packed with technology will detect even the smallest seismic waves to determine if there is any seismic activity on the Red Planet. SEIS is the result of a close 10-year collaboration between CNES and IPGP that is set to depart on NASA’s InSight mission to Mars on 4 March 2016.

Read the full press release.


Technological challenge, the seismometer SEIS has been developed in France by technical and scientific team from CNES, the Institute of Earth Physics of Paris (IPGP) (CNRS / Université Paris Diderot ), Space campus of the University Paris Diderot, the Higher Institute of Aeronautics and Space (ISAE ) and company SODERN. Several European and American laboratories ( Federal Polytechnic in Zurich (ETH), the Max Planck Institute for Solar System Research (MPS) in Lindau, Imperial College London and the Jet Propulsion Laboratory in Pasadena, California ) also contributed to the technological development and the company EREMS Toulouse .
Other laboratories of the CNRS and French universities will finally be associated with data analysis (LPG Nantes, Toulouse IRAP ). GéoAzur (Nice ) and the network " Seismo at School" contribute to the dissemination of meteorological and seismological data from the mission to schools and colleges.

One of the challenges of INSIGHT mission will be to install the surface of March 1 VBB seismometer ( broadband ), instrument on Earth usually installed in seismic cellars, where the temperature and pressure are usually very stable. It was therefore necessary for it to develop a wind and heat shield covering the seismometer as well as the soil around the sensor . This protection will be more insensitive to Martian storms and strong winds « dust devils ». The shield, of several kilograms, will be directed by the Jet Propulsion Laboratory, and use a high-performance airgel thermal protection.
A first prototype of this shield was tested in Reunion end of December 2011 , with the help of teams Volcanological Observatory of Piton de la Fournaise and the Max Planck Institute in Lindau , taking advantage for this land almost " Martian " of the piton de la Fournaise and significant temperature changes in altitude during the austral summer . Other tests on the various subsystems of the seismometer INSIGHT were also performed regularly for several years in the simulation center Martian ( IPGP / CNRS / IDF / CNES).


IPGP: recognized expertise

For 30 years, and the creation of a global network of seismological stations GEOSCOPE , researchers and engineers from IPGP develop, in collaboration with EOST , multiparameter stations that are installed in 23 countries to ensure uniform coverage of the earth. Stations transmit data in real time and are used for the detection of earthquakes and tsunami warning and for scientific research.
Stations have a broadband seismometer , a barometer , a thermometer and in seismic regions , also an accelerometer. Materials selection and design of the stations are defined to minimize noise and to increase the reliability of installations . Seismometers used are STS1 , created 30 years ago by Strekeisen , which remain to this day the most powerful broad - band seismometers land. Gradually, the isolation techniques of these stations have evolved which helped to greatly improve the signal/noise ratio .
These terrestrial, fragile and heavy instruments, are unusable for space missions. For these last , CNES, Space and planetary geophysics team IPGP and SODERN have therefore developed an entirely new sensor which is able to withstand vibration, shock, radiation and other constraints of a planetary mission. 20 years after the failure of the Mission MARS96 that already embarked two seismometers first generation, INSIGHT crown so nearly 25 years of efforts.